Blow molded articles provide a cost advantage over many articles that are formed of metal or other materials in that they are less expensive to manufacture and material costs are typically less. Further, the plastic can be recycled more easily providing environmental benefits. However, in some applications using prior blow molding techniques, panels often lacked the required local and overall rigidity that could accomplished with a metal structure. For example, a blow molded tray would normally have bottom and top surfaces connected by side walls, the side walls being smaller in surface area/height. As the blow molded article is increased in size, the distance between the side walls increases and the individual walls corresponding to the top and bottom surfaces will begin to deform more and more as loads are placed thereon.
One solution to this problem is to provide for increased wall thickness, which may thereby reduce localized bending (i.e. buckling of the walls). However, this solution has limits because as the wall thickness increases, so to do costs.
In addition, structural components of blow molded articles need to account for the necessity that fluid (such as air) needs to flow within the cavity of the article during molding to force the heated plastic against the mold surfaces and provide the desired shape. Restriction of fluid flow could also cause wall thinning beyond what is acceptable in the part design.
What is therefore desired is an improved structural component of a blow molded article which provides for appropriate wall thicknesses and reduces localized bending of walls and increases the overall strength and/or rigidity of the part.